Bump grunt from 1.4.1 to 1.5.2 in /Build

Bumps [grunt](https://github.com/gruntjs/grunt) from 1.4.1 to 1.5.2.
- [Release notes](https://github.com/gruntjs/grunt/releases)
- [Changelog](https://github.com/gruntjs/grunt/blob/main/CHANGELOG)
- [Commits](gruntjs/grunt@v1.4.1...v1.5.2)

---
updated-dependencies:
- dependency-name: grunt
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Build/package.json

@@ -13,7 +13,7 @@
   "license": "GPL-3.0-or-later",
   "homepage": "https://dfgviewer.de",
   "devDependencies": {
-    "grunt": "^1.3.0",
+    "grunt": "^1.5.2",
     "grunt-contrib-less": "^2.0.0",
     "grunt-contrib-watch": "^1.1.0",
     "grunt-terser": "^2.0.0",